1. Field of the Invention
This invention relates generally to a model helicopter device, and more specifically to a model helicopter device having such a construction that the acceleration of the revolution of a main rotor is detected and the pitch of tail rotor blades is adjusted in accordance with the detected acceleration to cancel a countertorque generated in the helicopter body by changes in the revolution of the main rotor.
2. Description of the Prior Art
In the conventional type of model helicopter, a tail rotor is rotated in proportion to the revolution of the main rotor. However, when the revolution of the main rotor is suddenly changed, a countertorque is temporarily produced in the helicopter body. Among means for preventing such a countorque included are;
(1) An operator remotely controls the pitch of tail rotor blades together with the control of the rotating speed of the main rotor by means of a radio control device. PA0 (2) A gyro is incorporated in the model helicopter to control the tail rotor by detecting a relative displacement angle between the gyro axis and the axis of the helicopter body. PA0 (3) The tail rotor is controlled by electrically detecting the differential of the revolution of the main rotor.
All these conventional means are not desirable since Method (1) requires a skill in operating the radio control device and involves difficulty in operation, Method (2) becomes effective only when a relative displacement is caused and involves difficulty in minute control due to poor detecting sensitivity, and Method (3) requires a complicated and expensive control circuit.
This invention is intended to obviate the aforementioned problems by cancelling a countertorque generated in the helicopter body by a change in the revolution of the main rotor by detecting the magnitude of acceleration of the revolution of the main rotor when the revolution of the main rotor is changed, and automatically adjusting the pitch of the tail rotor blades in accordance with the detected magnitude of acceleration.